An organic electroluminescence device (referred to below as “organic EL device”) which uses an organic electro-luminescence material can emit light in each color of the visible light band which is originally white emitted light by selecting the organic material or adopting an appropriate structure for the light emitting device. As a result, the development of display devices or lighting which use light emitting device is progressing.
A display device which uses a light emitting device is provided with light emitting devices in each pixel which are connected to a transistor and the emitted light is controlled by the transistor. The light emitting device is formed in a device substrate formed with the transistor. The display device is formed including a pixel array in which these type of pixels are provided in a matrix shape and the light emitted from the light emitting device is emitted to an opposing substrate which is provided facing the device substrate or above the device substrate and thereby a display screen is formed on the surface.
In the structure of a pixel, an interlayer insulating layer is generally provided between a light emitting device and a transistor. In addition, the light emitting device is provided with a layer including an organic electro-luminescence material (referred to below as “light emitting layer”) between a pair of electrodes as a light emitting material and one of the electrodes of the light emitting device is electrically connected with a source-drain electrode of the transistor in a contact hole formed in the interlayer insulating layer. In addition, because the light emitting device rapidly deteriorates when exposed to oxygen etc., the surface is sometimes covered using a sealing layer comprised from silicon nitride and the like.
When external stress is applied to a display device provided with this type of structure, interlayer peeling sometimes occurs at the boundary between the light emitting layer and electrode etc. included in the light emitting device or at the boundary between a sealing layer and light emitting device.
In order to control this peeling problem, the display device disclosed in Japanese Laid Open Patent No. 2013-077382 attempts to increase adhesion at the boundary between layers by forming a plurality of convex structured bodies using the same material as an electrode in a region sandwiched between electrodes of adjacent pixels, forming each layer up to a sealing layer from an organic compound layer above the convex structured body and increasing the contact surface between adjacent layers in a stacking direction using a concave-convex shape formed on the surface of each layer.
The display device which uses the above mentioned conventional light emitting device attempts to control interlayer peeling by following the concave-convex shape of the convex shaped structured body of the organic compound layer, electrode and sealing layer in order to increase the surface area of adjacent interlayers in each stacked layer. However, because there is no change in adjacent layers themselves in stacked thin films when a concave-convex surface is formed in each layer, there is no change in adhesion between a layer located on a lower layer and the layers stacked above and therefore there is a danger that interlayer peeling cannot be controlled.
In addition, in the display device which uses the above mentioned conventional light emitting device, when a concave-convex surface is formed in a plurality of layers provided above a concave shaped structured body, the concave-convex shape of the surface becomes gradually smaller towards the upper layer due to the thickness of the lower layer, adhesion between adjacent layers in the stacking direction becomes weaker die to planarization of the concave-convex surface and there is a danger that interlayer peeling occurs.
Therefore, one embodiment of the present invention aims to prevent interlayer peeling between a light emitting device and an adjacent layer and provide a display device for which a high level of reliability can be secured. In addition, another aim of the present invention is to realize this simple structure without significantly modifying a manufacturing process.